Antibody-drug conjugates (ADCs) can provide an effective means of delivering a drug to a targeted site in a tissue or organism. Recognition of a target such as a tumor by the antibody minimizes exposure of non-target tissues to toxic chemotherapeutic agents and limits adverse effects associated with the toxicity of “free” drugs (i.e., unbound to a carrier such as an antibody). ADCs can be prepared by a number of techniques. Prior to administration to a human or other subject, the conjugate is purified to remove free drugs and other impurities.
Due to the very high potency of benzodiazepine containing drugs, the removal of free drug-related impurities from a mixture comprising benzodiazepine ADCs and benzodiazepine drug-related impurities needs be highly effective. The present invention addresses this and other needs.